#human chimerism

[kiminoan]

Not to be SUPER pedantic, but how can there be twins with heterochromia? Heterochromia is a byproduct of chimerism. You would have to have quadruplets that were two pairs of identical twins that were absorbed by their fraternal twins in the same way, wouldn't you? wat.

[starryoak]

One thing that I think is an understated sadness in the JLU episode “Epilogue”,  is that while it’s not explicitly stated, along with the reveal of who Terry is, that also tells you the likely reason Warren and Mary McGinnis divorced. After all, Warren, unbeknownst to him, had his own genetic material overwritten with Bruce’s, so that they could make another Batman eventually; it’s both an interesting explanation as to why Warren and Terry/Matt look nothing alike, but it… also kind of tells you that it’s likely the reason Mary and Warren divorced is because Warren believed Mary was cheating on him.

And, well, there wouldn’t be anything to disprove that! Genetically, Terry and Matt aren’t Warren’s children. But that basically means that Mary wouldn’t be able to explain or defend herself because, even if she had never slept with anyone in her life but Warren, she would always be seen as lying, because even an objective analysis would indicate she had to be.

It actually reminds me of a few cases like that in reality, not the idea of genetic information being overwritten, but a real life case of someone’s children not being their biological children despite objectively giving birth to them; Lydia Fairchild was a woman who, during a routine paternity test to enforce child support, seemingly was not the mother of her two children, while her ex-partner was the father, she was not! She stood accused of fraud as a result of this, and as she was pregnant with her third child at the time, the court ordered a witness present at the birth to collect blood samples and testify in court. When the DNA tests returned, she was apparently not the mother of the baby in question either, despite the obvious evidence to the contrary! Her defense attorney uncovered a similar case to Lydia’s where another mother had been found to not be the biological parent of her own children, it had been uncovered that this was due to a condition called chimerism; when fraternal twin zygotes merge into one singular being in the womb, this leads to the person being born with two distinct sets of DNA. When DNA from her parents were collected, Lydia’s children were found to be her parent’s grandchildren, and when DNA from a cervical swab was tested, what do you know? Her children’s biological parent was her own unborn twin!

Yes, this entire damn post was an excuse to share an interesting medical fact, if you were wondering.

[bluewolf7998]

So evidently (from searching google) it isn't normal for someone to have both central and sectoral heterochromia. Which kind of leads me to consider my chimerism theory, but honestly I don't know enough biology or genetics to move forward with figuring it out.

My primary care with Penn State Health tried to direct me to John's Hopkins for testing, but their representative who called me 2 months later said they don't test for chimerism outside of acquired microchimerism from transplants.

I just would really appreciate someone who knew more than me helping to figure this stuff out, because it makes sense to me, with a few other symptoms. But again, at this point I can only say it's a theory, and I feel like a crackpot bringing up to Penn State Health again, considering their first response was to refer me to a place that doesn't test for from-conception chimeras.

I could ask for a blood test to see if I maybe have a mixed blood type, but again, I'd sound like a hypochondriac.

TLDR; I'm frustrated not knowing more about biology or genetics, and all my local options for more information have been depleted. Biologists, geneticists, or people who know more, please help. I need a direction to go.